Algorithm 892: DISPMODULE, a Fortran 95 module for pretty-printing matrices

A standard Fortran 95 module for printing scalars, vectors, and matrices to external files is provided. The module can display variables of default kind of all intrinsic types (integer, real, complex, logical, and character), and add-on modules are provided for data of the nondefault kind. The main module is self-contained and incorporating it only requires that it be compiled and linked with a program containing a “use dispmodule” statement. A generic interface and optional parameters are used, so that the same subroutine name, DISP, is used to display items of different data type and rank, irrespective of display options. The subroutine is quite versatile, and hopefully can improve Fortran's competitiveness against other array programming languages. The module also contains a function TOSTRING to convert numerical scalars and vectors to strings.